1. Field of the Invention
This invention relates, in general, to air conditioning apparatus. In particular, the invention relates to a portable air conditioning apparatus which includes an evaporation type condenser and an evaporator disposed in an common casing, which may be moved to a desired place.
2. Description of the Related Art
As shown in FIG. 1, a well known portable air conditioning apparatus 11 typically includes an evaporation type condenser 13 and a spray device 15, which sprays water on evaporation type condenser 13. A casing 17 of air conditioning apparatus 11 is partitioned into an upper chamber 19 and a lower chamber 21 with a partition plate 23. An air discharging opening 25 is formed in the front surface of casing 17. An air intake opening 27 is formed in the rear surface of casing 17. A fan casing 28 is arranged in upper chamber 19, and opens to air discharging opening 25. An internal fan 29 is rotatably disposed in fan casing 27, is supported by one of the rotatable shafts 30a of a two-shaft motor 30 arranged in lower chamber 21. An evaporator 31 and an auxiliary heat-exchanger 33 arranged parallel to evaporator 31 are disposed in upper chamber 19 so as to be opposite to air intake opening 27.
An exhausting fan 35 and the above-described spray device 15 are coaxially supported by the other rotatable shaft 30b of two-shaft motor 30 in lower chamber 21. Exhausting fan 35 is a centrifugal fan device, and is disposed between two-shaft motor 30 and spray device 15. An exhausting fan casing 37 is disposed around exhausting fan 35. A flexible air guide hose 39 is inserted into an outlet 37a of exhausting fan casing 37 to guide air from exhausting fan 35 to the external atmosphere. A second air intake opening 41 is formed in the rear surface of casing 17 close to outlet 37a of exhausting fan casing 37 to take external air into lower chamber 21 of casing 17. Spray device 15 includes a cylinder 15a, the diameter of which gradually increases from the lower end toward the upper end. A plurality of fins (not shown) extend from the inner peripheral wall of cylinder 15a toward rotatable shaft 30b, and each extended end of the fins is fixed to a hub (not shown) which is firmly fixed to rotatable shaft 30b of motor 30. The lower end of cylinder 15a of spray device 15 is dipped into water in a water tank 43 disposed on the bottom surface of casing 17. Water tank 43 is partitioned into two vessel portions. The lower end of cylinder 15a extends into water in one of the two vessel portions. A water supply pipe of a water storage tank (not shown) extends into the water in the other vessel portion of water tank 43. One end of a drain hose (not shown) is connected to the other vessel portion of water tank 43, and the other end of the drain hose is connected to a drain tank (not shown). Drain water condensed on evaporator 31 and auxiliary heat-exchanger 33 is collected in the drain tank, and is stored in water tank 43 through the drain hose. Water tank 43 is provided with a float switch 47 to detect the level of water stored in water tank 43.
As shown in FIG. 1, evaporation type condenser 13 is coiled around the periphery of cylinder 15a of spray device 15 so as to maintain a predetermined distance between coiled condenser 13 and cylinder 15a. A cylindrical cover 49 is disposed outside condenser 13 to prevent water from being scattered to lower chamber 21. A refrigerating circuit of the above-described air conditioning apparatus includes evaporation type condenser 13, evaporator 31, auxiliary heat-exchanger 33, and other components (not shown), such as, e.g., compressor, capillary tube, etc.
When the cooling operation is executed by the above-described conventional air conditioning apparatus, the compressor (not shown) and two-shaft motor 30 are operated. Thus, internal fan 29, exhausting fan 35, and spray device 15 are driven by motor 80. Internal air is taken into upper chamber 19 of casing 17 through air intake opening 27, and is cooled by evaporator 31 and auxiliary heat-exchanger 33. The cooled internal air is supplied to a defined space to be cooled. When exhausting fan 35 is driven, the internal air also is taken into lower chamber 21 of casing 17 through second air intake opening 41 to cool condenser 13. After cooling condenser 13, air is exhausted to the outside of the defined space through exhausting fan 15 and air guide hose 39. At this time, spray device 15 also cools condenser 13. Water in water tank 43 is drawn up by spray device 15, and is sprayed from the upper end portion of spray device 15 in the centrifugal direction. Thus, the sprayed water falls on condenser 13 to cool condenser 13. After that, water is collected in water tank 43.
In the above-described air conditioning apparatus, since water sprayed onto condenser 13 which has a relatively high temperature tends to evaporate, the level of water in water tank 43 rapidly decreases. To control the decrease of water in water tank 43, the air conditioning apparatus is provided with a water supply tank (not shown) therein. When water is evaporated because of condenser is having a relatively high temperature, and the water level in water tank 43 detected by float switch 47 decreases, water in the water supply tank is automatically supplied to water tank 43. However, in the conventional air conditioning apparatus, the installation space for the water supply tank is restricted by the external size of the air conditioning apparatus. It is rather difficult to install a water tank having a desirable large water storage capacity in the air conditioning apparatus. Therefore, the period for which the water level in water tank 43 can be maintained to cool evaporator 13 is relatively short, e.g., four hours, in an average air conditioning apparatus. It is rather troublesome to frequently replenish the water supply tank with water.